Grinding machine



1936- H. L. BLOOD ET AL 2,050,482

GRINDING MACHINE Filed June 25, 1934 5 Sheets-Sheet 1 m Ma /6% Aug. 11, 1936. H. 1.. BLOOD ET AL GRINDING MACHINE Filed June 25, 1934 5 Sheets-Sheet 2 Aug. 11, 1936.

H. L. BLOOD ET AL GRINDING MACHINE Fil ed June 25, 1954 5 Sheets-Sheet 3 flroea? I. Blood jfalzer Fae/(ever 1936- H. L. BLOOD ET AL i 2,050,482

GRINDING MACHINE Filed June 25, 1954 5 Sheets-Sheet 4 gwuwvbom firold' 51000? Jfdlt'er KHa/(erzer Patented Aug. 11, 1936 GRINDING MACHINE Harold L. Blood, Birmingham, Mich., and Walter H. Pickener, Worcester, Mass.,- asslgnors to The Heald Machine Company, Worcester, Mass a corporation of Massachusetts Application June 25,1934, Serial No. 732,238

, 32 Claims.

The present invention relates to a grinding machine for the successive reduction of a pinrality of workpieces all to a predetermined size,

and it is particularly applicable to a machine for s grinding the internal surfaces of sleeves, bushings,

or like articles.

In the copending Blood and Burns application,

7 Serial No. 684,210, flled August 8, 1933, now U. S.

Patent 2,027,627 dated January 14, 1936, the

workpiece is positioned in a centerless worksupporting structure and is ejected therefrom, when completed, in response to the axial separation between the workpiece and the internal grinding wheel. This structure isentirely satisfactory in operation; however, when the machine is arranged for grinding tapered workpieces, such a machine involving either a tumable workhead of a turnable wheelhead, the mechanical elements for actuating the ejector are necessarily complicated. It is accordingly one of the principal objects of the present invention to avoid this objection by providing for fluid pressure actuation of the ejector, by which the workpiece is discharged from the work-supporting structure. By this arrangement, the work-supporting structure, as an entire unit, may be mounted for turning movement about a vertical axis to provide for grinding of tapered workpieces.

In the use of a gage mechanism of the type disclosed in the Kempton and Gallimore Patent No. 1,731,719, datedOctober 15, 1929, in connection with a centerless work-supporting structure from which the workpiece is discharged radially by an ejector, it is essential that the gage be fully retracted from the bore of the workpiece before the ejector begins its operation to avoid damage to the machine. It is accordingly a further object of the present invention to provide an interconnection between the gage retracting mechanism and the ejector to assure a positive withdrawal of the gage before the workpiece is discharged.

In order that the machine may be entirely automatic and operate satisfactorily on successive workpieces, there must be a definite and certain retumof the ejector to original position to assure the positioning of an unground workpiece in the work-supporting structure before the grinding wheel is moved axially relative to the workpiece to bring said wheel into operative posi- 50 tion. To this end, the present invention provides for an interlocking arrangement which provides for a relative axial movement of the grinding wheel into operative position at the beginning of a grinding operation only when the ejector 5 has'reached a predetermined position, thereby assuring the positioning of an unground workpiece within the work-supporting structure.

Other and further objects andadvantages of the invention will appear from the following detailed description taken in connection with the 5 accompanying drawings in which:-

Fig. 1 is a front elevation of a machine embodying the invention.

Fig. 2 is a vertical sectional view substantially along the line 22 of Fig. 1, showing the work- 10 supporting structure with the grinding wheel in operative position.

Fig. 3 is a fragmentary elevation through the workhead, showing the gage structure, with parts broken away to show more clearly the construc- 15 tion.

Fig. 4 is a vertical sectional view showing the driving means for the regulating wheel and the ejector actuating structure.

Fig. 5 is an end elevation of the structure of 20 Fi 4.

Fig. 6 is an enlarged elevation of the control mechanism mounted on the front of the machine.

Fig. is a sectional view through the cross- 2 feed mechanism.

Fig. 8 is a sectional view substantially along the. line 88 of Fig. 4.

. Fig. 9 is a fluid pressure diagram.

Like reference characters refer to like parts in 30 the different figures.

Referring first to Fig. 1, the machine provides the usual reciprocatory table I provided in an internal grinding machine; either the grinding wheel or the work to be ground is carried on said 35 table, the reciprocations of the latter operating in either case to produce a relative translatory movement between said grinding wheel and the workpiece. In the construction shown, the table supports and carries a workhead 2 and the wheelhead 3 is mounted on a bridge 4 which spans the guideways, not shown, provided by the base 5 of the machine for the movements of the table I. The grinding wheel 6 is carried on a spindle I journaled in the wheelhead 3 and is suitably rotated at a high rate of speed byany well-known mechanism, not shown. The workpiece a, Fig. 2, is mounted in the work-supporting structure on the workhead and is also rotated at a slow rate of speed, as will hereinafter appear.

The reciprocations of the table I which cause the rotating grinding wheel to make the desired traverse over the surface of a workpiece inthe work-supporting structure are imparted in any well-known manner as by the use of fluid pres- 55 sure controlling and reversing mechanism, one type of which is described in the Heald and Guild Patent No. 1,582,468, dated April 27, 1926. It is suilicient to note, for the purpose of the present application, that reversal of the table is procured at each end of the normal working stroke by spaced adjustable dogs 3 and 3 Fig.6, which are carried by blocks III and II adjustably mounted on the table I and which are adapted alternately to engage and move a reversing member I2. The latter provides spaced upwardly projecting lugs I3 and I4 (see Fig. 6) which, during the grinding operation, when the workpiece is reciprocated back and forth over the grinding wheel, are situated in a position to be engaged by the dogs 3 and 8 respectively. The movements of the member I2 procure reversal of the movements of the table I through suitable mechanism to be described later.

Referring now to Fig. 9, fluid under pressure, which is supplied by a pump I5, is directed through suitable valve mechanisms, hereinafter described, to the inlet port I5 of a casing I! in which a reversing valve I8 is positioned. The valve casing I8 has outlet ports I9 and 20 connected by pipes 2| and 22 respectively to a port 23 in the right hand end of a cylinder 24, and a port 25 spaced from the left hand end of said cylinder, as indicated, for a purpose which will hereinafter appear. The cylinder is mounted within the base of the machine, and a piston 25 which is slidable within the cylinder has a projecting piston rod 21 which is secured to a depending lug 28 Fig. 4 on the under side of the table I. The reversing valve I 8 alternately directs fluid under pressure through the pipes 2| and 22 to the cylinder at opposite sides of the piston for urging the table I alternately to the right and to the left. At the same time, fluid exhausts from the opposite end of the cylinder through an exhaust port 29 in the casing II.

The reversing member I2 is connected to the reversing valve I8 for actuating said valve in response to the shifting movements of said member. As best shown in Fig. 6, the forward end of Y the reversing valve I8 has secured thereto an arm 30 which supports a pin 3| in spaced relation to the center line of the valve. Said pin is positioned between spaced projecting lugs 32 and 33 on the end of an arm 34 secured to a shaft 35 journaled in the control box 35 on the front of the machine. The reversing member I2 is also secured against turning movement on the shaft 35 so that said member and the arm 34 move as a unit. The arm 34 has a V-shaped projecting portion 31 which engages with a corresponding V-shaped lug 33 on the end of an arm 39 pivotally mounted on a pin 40 carried by a bracket 4I secured within the control box. The arm 39 is urged upwardly into engagement with the V- shaped portion 31 by a spring 42.

As will be apparent from the drawings, the spacing between the lugs 32 and 33 is materially greater than the diameter of the pin 3i to provide' a lost motion between the arm 34 and the reversing valve. As the arm 34 is rocked by either of the reversing dogs 8 or 9, the v-shaped portion 31 slides along the side of the V-shaped lug 33 with which it is in engagement until the points of the V-shaped portion and lug pass each other. The arm 34 is then moved positively through the remainder of its travel by the action of the spring 42 and shifts the valve I8. A positive reciprocation of the table is thus procured in response to oscillation of the reversing member I2 by the reversing dogs 3 and I.

For. shifting the reversing valve manually in setting up the machine, the arm 34 carries a pin "which is positioned between spaced arms 44 6 and 45 provided by a plate 43. The latter is secured to a shaft 41 journaled in the control box and projecting through the cover ,Fig. 1. of said box, carrying on the forward end thereof a lever 48 which provides for manual turning 10 movement of the shaft. The arms 44 and 45 are spaced apart a distance substantially greater than the diameter of the pin 43 to permit the arm 34 to rock without a corresponding movement of the lever 49, during the automatic oper- 15 ation of the machine.

The crossfeed movement between the workpiece in the workhead and the grinding wheel is obtained by transverse movement of the wheelhead 3 on the bridge 4. The wheelhead is mount- 20 ed on a cross-slide, not shown, and movement of said cross-slide is obtained by rotation of a crossfeed screw 50, Fig. 7, which engages an internally threaded portion, not shown, of the cross-slide. Said crossfeed screw carries a ratchet wheel II 25 secured against turning movement thereon, the latter being in a position for engagement with oppositely acting pawls 52 and 53 carried on studs 54 and 55 on an annular member 53 journaled on the crossfeed screw.

During the crossfeed movement of the grinding wheel, which is procured by a positive clockwise rotation (Fig. 1) of the annular member 56 through mechanism hereinafter described, the pawls are carried clockwise with said member, 35 and the pawl 53 procures a positive rotation of the crossfeed screw. As the grinding operation continues, a pin 51 on the pawl 52 is brought into engagement with a shield 58 adjustably positioned in the casing 59 in which the crossfeed mechanism is located. Said shield procures retraction of the pawl 52 from the ratchet wheel 5I, but the crossfeed movement continues under the action of pawl 53 until the grinding is completed. During a subsequent retraction of the 5 crossfeed movement by a counterclockwise turning movement of the annular member 56, the latter turns through a greater distance than the ratchet wheel since the pawl 52 is inoperative until the pin on said pawl moves out of engage- 50 ment with the shield 58. The pawl 52 then being moved into engagement with the ratchet wheel by a spring 50, procures rotation of the ratchet wheel 5I during the remainder of the counterclockwise movement of the annular member 53,, 55 thus retracting the grinding wheel from its advanced position. The relative turning movement between the annular member 56 and the ratchet wheel 5I during the retracting movement provides a compensation for the reduction in size of so the grinding wheel, this compensation, as will be apparent, being substantially equal to the actual reduction of the grinding wheel.

For the fluid pressure actuation of the crossfeed mechanism, the annular member 55 has an 65 integral pinion 6|, Figs. 1 and 7, which is engageable with a vertical rack 62 on the upper end of a piston rod 63 secured to a piston 54 slidable in a cylinder 65 secured to the base of the machine. A roll 66, Fig. 1, holds the rack in engage- 7 ment with said pinion.

Fluid under pressure from the pump 15 passes through a pipe 61 (Fig. 9), to a channel 53 in a valve casing 63, the latter having a longitudinal bore 10 in which a valve member II is slidable. 75

The channel 88 Intersects the bore 10 at a point substantially opposite to the intersection of a channel 12 with said bore. The latter channel is connected by a pipe I3 to a port in the lower end of the cylinder 55, said pipe I9 preferably having a manually adjustable throttle valve I4 therein for controlling the rate of crossfeed movement.

The upper end of the cylinder 85 is connected by a pipe 15 and a pipe I8 connecting therewith to a channel I1 in the casing 89. Said channel 11 also intersects the longitudinal bore I0 and fluid connection is normally provided from said channel to an exhaust channel 18 in the casing 99 by a reduced portion 19 of the valve member II adjacent the right hand end thereof. As fluid under pressure passes into the lower end of the cylinder 65, the upward movement of the piston procures a corresponding clockwise movement of the annular member 58 for a crossfeed movement of the grinding wheel, fluid from above the piston exhausting at this time through the pipe 15 to the exhaust channel. The retraction of the grinding wheel by a downward movement of the piston is procured by directing fluid under pressure to the upper end of said cylinder, as will hereinafter appear.

The function and shifting movements of the valve II, so far as it controls the movements of the table, are fully described in the copending Blood and Burns application, Serial No. 681,334, filed July 20, 1933, now U. S. Patent 2,011,705, dated August 20, 1935. For the purposes of the present application, it will be sufilcient to note that the casing 69 (Fig. 9) has a channel spaced from the channel 88 and connected by a pipe II to a channel 82 in a casing 83 having a longitudinal bore 84 therein in which the main throttle valve 85 is positioned. The latter has a longitudinal recess 85 therein which is open to the inner end of the bore 84 and the end of said bore is connected by a pipe 81 to the inlet port I5 in the reversing valve casing IT. The throttle valve 85 has a triangular notch 88 adjacent to the intersection of the channel 82 with the bore 94 to provide fluid connection between said channel 82 and the recess 86 in the valve. The triangular shape of the notch 88 provides for throttling the flow of fluid to the table cylinder by adjusting the angular position of said throttle valve. With the valve II in the position shown, fluid connection is provided between the channel 59 and the channel 82 by the reduced portion 89 of the valve II between the full-sized portions 90 and 9| thereof.

For retraction of the cross-feed movement the valve 'II has a channel 92 therein which is open at one end to the reduced portion 89 of said valve and at the other end intersects with an annular groove 93 formed in the full-sized.portion SI of said valve. When the valve II is shifted into its right hand position at the end of the grinding operation by mechanism hereinafter described, fluid under pressure from the channel 88 passes through the channel 92 into the groove 98, which is then in alignment with the opening into the channel 11, thereby directing fluid under pressure through the pipe I8 and the connecting pipe 15 into the upper end of the cylinder 85 to procure a downward movement of the piston 84 and a corresponding retraction of the crossfeed movement.

The pipe", forming part of the connection to the upper end of the cylinder 65, is connected to a port 94 in the upper end of a casing 95 in which a valve 90 is positioned, the latter being normally retained in its upper position, shown by a spring 91. The casing 95 also has a port 98 spaced from the port 84 and connected by a short pipe 99 to the pipe 13 which is connected 5 to the lower end of the cylinder 65. The flow of fluid from the pipe 89 to an exhaust port I00 in the casing 95 iscut oil. by the valve 98 during the crossfeed movement. As fluid under pressure enters the upper end of cylinder 65 for retract l0 ing the crossfeed movement, fluid under pressure also enters the upper end of the casing 95 and moves the valve 96 downwardly to provide an exhaust connection between the ports 98 and I00 for fluid from the lower end of the-cylinder 65.

The workpiece a is supported in a centerless work-supporting structure mounted on the table I. As shown in Figs. 2 and 4, the workhead 2 has a spindle IOI iournalled therein, and a regulating wheel I02 of large diameter is carried on the 20 inner or right hand end thereof for engagement with the periphery of the workpiece a, as best shown in Fig. 2. Forwardly of the regulating wheel I02, and-in the same vertical plane, is. positioned a work-supporting wheel I03 mounted on a slide I04 adjustable on a bracket I05 secured to the table, said wheel also engaging with the periphery of the workpiece. An adjusting screw I06, which is held against axial movement in a lug I 0'I on the bracket I05, engages the slide I04 30 to provide for adjustment of the position of the supporting wheel relative to the regulating wheel. The workpiece a. is held in engagement with the regulating and supporting wheels by a pressure wheel I08 on a shaft I09 in the end of an arm H0 35 which is secured against rotation on a shaft III journaled in the workhead, said pressure wheel being resiliently held against the workpiece, as will hereinafter appear. The spindle IN is positively rotated by a driving motor, not shown, connected by V-belts to a pulley I I3 on said spindle. Rotation of the wheel I02 procures a corresponding rotation of the workpiece a by engagement with the periphery thereof, this rotation of the workpiece being clockwise as seen in Fig. 2. The workpiece is thus supported and rotated on the cylindrical outer surface thereof during the grinding operation.

As shown in Fig. 3, the workpiece is held against axial movement by a rotating backing plate II4 which is rotatable about an axis coinciding substantially with the axis of the workpiece, and which is supported by bearing surfaces II5 forming a part of the workhead. The backing plate has a cylindrical flange H8 which engages with the end surface of the workpiece, the latter being urged axially against said flange by the action of the pressure wheel I09, whose axis extends at a slight angle to the axis of the workpiece.

The grinding operation is under the control of a gage member I I1, Fig. 3, which is carried on the end of a gage rod II8 longitudinally slidable in the workhead. The gage rod extends through an opening H9 centrally of the backing 65 plate II4 so that the gage member II! is supported in alinement with the bore of the workpiece. The outer or left hand end of the gage rod II8 has an arm I20 journaled thereon, said arm being supported against axial movement by 70 hearing members I2I. The lower end of said arm is secured against movement on the end ofa. rod I22 which is longitudinally slidable in a bore I28 in the workhead. The right hand end of the rod I22 projects to the right beyond the 75 workhead, as shown in Pig. 1, and is normally in alinement with the head of an adjustable screw I24 mounted in a bracket I25 on the bridge 4. A spring I26 in an opening I21 within the workhead surrounds the rod I22 and engages, at one end, with a sleeve I26 on said rod, said sleeve being suitably held against movement on said rod. The other end of said spring engages a portion of the workhead for normally urging the rod I22, which is parallel to the gage rod H6, to the right, thereby urging the gage II1 against the end of the workpiece.

The rod I22 supports a forwardly projecting arm I23 adjacent the arm I20, and an adjustable screw I30 is held in adjusted position in the outer end of said arm by a locking nut I3I. At the beginning of the grinding operation, before the workpiece is sufficiently large to permit entry of the gage, the right hand movement of the screw I30 relative to the workhead is limited by engagement of said gage with the end of the workpiece. When the bore of the workpiece is suiiiciently enlarged by the grinding operation, the gage II1 enters said bore, providing an extended movement of the screw I30 to the right for procuring a run-out of the table to the position of Fig. l, as will hereinafter appear.

The control mechanism, by which the movements of the table are procured, may be of the type fully disclosed in the above cited copending application of Blood and Burns, Serial No. 681,334, filed July 20, 1933. It is sufficient to note for the purpose of the present invention that, as best shown in Figs. 1 and 6, a lever I32, which is journaled on a shaft I33 positioned in the control box 36 has a depending arm or latch I34 which normally engages a notch I35 provided in a lug I36 on a depending arm I31 journaled on a shaft I38 in the control box. Said arm is urged counterclockwise by a spring I33 which is positioned in a recess I40 in a bracket I mounted in the control box, one end of said spring engaging the inner end of the recess and the other end of said spring engaging said arm. A bell crank lever I42 which is journaled on the shaft I30 has a depending arm I43 which engages a pin I44 on the arm I31. The other arm I45 of the bell crank lever I42 projects upwardly between the lugs I3 and I4 on the reversing member I2 and is provided with a cam surface for engagement with the reversing dog 3 which is pivotally mounted on a pin I46 in the block II.

The lever I32 has an upwardly extending arm- I41 which projects through an opening I48 in the control box. The table I carries a block I49, Fig. 1, which supports a pin I50 on which a bell crank lever I5I is pivotally mounted. The latter is received within a slot I52 in said block and is held frictionally against unintended movement therein. One arm I53 of the lever I5I extends substantially horizontally to the right and slightly above the upper end of the arm I41 and the opposite arm I54 of said lever extends upwardly into horizontal alinement with the adjustable screw I30 connected to the gage mechanism. During the grinding operation, the ad justab e screw I 30 does not move sufiiciently to the right to engage and rock the lever I5I. When the gage I I1 enters the workpiece, however, the extended movement of the screw I30 resulting from said entry turns the lever I5I clockwise and moves the end of the horizontal arm I53 thereof downwardly into alinement with the end of the arm I41.

n the subsequent movement of the table I to the right, after the rockingof the lever II, said lever engages and rocks the lever I32, thereby releasing the arm I31 to permit movement thereof to the right for elevating the upwardly 5 extending arm of the bell crank lever I42. Said arm in its upper position is in.a1inement with the reversing dog 9 and prevents engagement between said dog and the reversing member during movement of the table to the left so that the table moves to the inoperative position of Fig. l, to withdraw the grinding wheel from the workpiece.

The arm I31 engages at its lower end in a notch I55 provided by the valve 1|, and the swinging movement of said arm to the right, shifts said valve for procuring a retraction of the crossfeed movement, as well as other movements which will be hereinafter described. The valve movement to the right establishes fluid connection from the pump I5 to the upper end of the cylinder 65, as above pointed out, and the crossfeed movement is automatically retracted.

The above mechanism is all clearly disclosed 2 in the patents and applications above referred to, and is not of itself a feature of the present invention, the description having been incorporated herein for clarifying the operation of the novel mechanism hereinafter disclosed, and for disclosing a completely automatic machine. The hereinafter described structure, which is an embodiment of the present invention, operates in connection with the foregoing or similar mechanism in attaining the novel results above set forth.

Referring now to Fig. 9, the shifting movement of the valve H at the end of the grinding operation also procures a retraction of the gage member from within the bore of the finished workpiece. The workhead (see Fig. 3) is provided with a longitudinal bore I56 in which a piston I 51 is movable. A piston rod I58 projects to the left beyond the workhead and engages the head of an adjustable screw I59 in the arm I20 of the gage mechanism. The piston I51 is normally urged to the right by a spring I60 surrounding the piston rod. The right hand end of the bore I56 has a port I6I connected by a pipe I62, Fig. 9, to a port I63 in a casing I64. A piston valve I65 is vertically movable within saidcasing and is normally held in the lower position shown by a coil spring I66 engaging the end of said valve. A port I61 in said casing, in alinement with the port I63, is connected by a pipe I 68 to the pipe 16 which extends between the valve 1i and the upper end of the cylinder 65. As fluid under pressure is directed into the upper end of the cylinder 65 for the crossfeed retraction at the end of the grinding operation, fluid under pressure also passes through the pipes I68 and I62 into the bore I56, urging the piston therein to the left and retracting the gage from within the bore of the workpiece, since the valve I has a reduced portion I69 which provides a fluid con- 65 nection at all times between the ports I63 and I61.

During the runout of the table to rest position at the completion of the grinding operation, the finished workpiece or workpieces are removed 70 from operative position and unground workpieces are positioned therein. As shown in Figs. 2 and 4, the spindle I M which carries the regulating wheel I02 is hollow for the reception of a shaft I10 journaled therein. The latter carries on the forward end thereof a plate "I secured against movement thereon, and said plate has an ejector arm I12 which extends transversely across the surface of the wheel I02 in spaced relation thereto, the arm being normally beneath the workpiece as shown in Fig. 2. The plate "I has a slot I18 therein which receives the end of the shaft I10, a clamping nut I14 on the end of the shaft I supporting the plate in adjusted position thereon. The left hand end of the shaft I10 has a fluid motor I15 connected thereto, as will hereinafter appear, for actuatingsaid ejector arm, said motor procuring, during the runout of the table to rest position, a turning movement of the shaft I10 for a clockwise rotation (Fig. 2) of the ejector arm into the dot-dash line of Fig. 2. During this movement, the upper surface of the arm I12 engages the workpiece in the work-supporting structure and carries it around the periphery of the regulating wheel I02 to the top thereof where it is discharged toward the rear of the machine.

Referring again to Figs. 4 and 5, the shaft I10 carries a cam I16 which engages with a roller I11 on one end of a lever I18 journaled on a pin I19 secured to the workhead. The opposite end of the lever I18 has a flat surface I80 which engages with one arm of a bell crank lever I8I journaled on the outer or left hand end of the shaft III to which the arm IIO carrying the pressure wheel I08 is secured. The opposite arm I82 of the bellcrank lever extends upwardly between the opposite legs I83 and I84 of a U-shaped member I85 secured against turning movement on the shaft III. Set screws I86 and I81, which are positioned in the legs I83 and I84, engage opposite sides of the arm I82 to provide for adjustment of the bell crank lever I8I relative to the member I85.

A rod I88, Figs. 1 and 5, extends upwardly from a lug I89 on the workhead through a notch, not shown, in the end of the bell crank lever I8I. A spring I90 surrounds the rod and engages with the upper surface of the bell crank lever to maintain the latter in engagement with the surface I80. The upper end of the spring I90 engages a threaded sleeve I9I on the upper threaded end of the rod I88. Turning movement of the sleeve |9I adjusts the tension of the spring I90, thereby varying the downward pressure on the bell crank lever I8I and accordingly adjusting the pressure exerted by the pressure wheel I08 against the workpiece. During turning movement of the shaft I10 for ejecting the workpiece, the cam I16 on said shaft rocks the lever I18 to procure a clockwise movement (Fig. 5) of the bell crank lever I 8I and a corresponding retraction of the pressure wheel I08 (counterclockwise, Fig. 2) from engagement with the workpiece, permitting the workpiece to be easily elevated by the ejector from within the work-supporting member.

As shown in Fig. 2, the table I has an upwardly extending portion I92 on which a bracket I93 is mounted, the latter having parallel slots I94 which are engaged by bolts I95 to permit adjustment of said bracket relative to the table. The bracket I93 provides a U-shaped groove I96, Fig. 1, having a bottom surface I91 inclined downwardly toward the rear, the rearward end of the surface I91 being in substantially vertical alinement with the forward surface of the regulating wheel I02 to permit workpieces positioned in the U- shaped groove I96 to drop into the work-supporting member. The bracket I93 also provides an arcuate U-shaped groove I98 substantially parallel to the periphery of the wheel I02 and in alinement with the workpiece a in the worksupporting member, said groove extending from a point slightly above the workpiece to a point directly above the upper position of the ejector 5 arm and intersecting the groove I96.

The workpieces in the groove I96 are normally urged by gravity toward the rear of the machine into the position shown in Fig. 2 and are prevented from passing beyond the position shown by an arm I99 which engages the bracket I 93 in alinement with the workpieces in the groove I96. The arm I99 is secured against rotation on a shaft 200 journaled in: a bracket I, mounted on the workhead and said shaft has a horizontally extending arm 202 which engages the upper end of a vertical plunger 203 in a sleeve 204 provided by the bracket 20I. A cam 205 secured to the shaft I10 adjacent the plate "I engages, during the rotation of the shaft I10, with the lower end of the plunger 203, urging the latter upwardly to procure a clockwise tuming movement of the arm I99, for releasing the rearmost workpiece in the groove I96. A depending arm 206 secured to the shaft 200 engages a spring 201 which is positioned between the sleeve 204 and said arm 206 and which retains the arm I99 in the normal position shown.

The ejector arm I12, as shown in Figs. 2 and 4, is of a suflicient width to prevent the rearmost workpiece a in the groove I96, when released by the arm I99, from dropping between the groove I98 and the wheel I02 beneath said ejector arm. As the ejector arm returns counterclockwise to the position shown in full lines in Fig. 2, this movement occurring before the workhead begins its movement into operative position for a subsequent grinding operation, as will hereinafter appear, the workpiece a follows said arm downwardly, guided by the groove I98 and the ejector arm so that said workpiece is properly positioned in the work-supporting member in readiness for a grinding operation thereon.

As above stated, the finished workpiece is discharged when the ejector reaches the dot-dash line position of Fig. 2. From this position, the finished workpiece rolls by gravity toward the rear of the machine over a downwardly and rearwardly inclined surface 208 provided by a rearwardly extending portion 209 of the bracket 20I.

The fluid pressure motor which actuates the ejector is actuated by fluid from the main table cylinder and is operable only when the gage member has been completely retracted from the workpiece. As best shown in Fig. 8, the left hand end of the shaft I10 has secured thereto the piston or vane 2I0 of the oscillatory fluid motor I15, said vane oscillating in a semi-cylindrical opening 2 in a casing 2I2 secured, as shown in Fig. 4, to the workhead. Said casing 2I2 has a channel 2I3 which intersects the opening 2I I adjacent the top thereof, said channel being connected by a pipe 2I4 to a port 2I5 in the bore I56. The port 2I5 is spaced longitudinally from a port 2I6 which is connected by a pipe 2I1 to a port 2I8 in the valve casing I64. Fluid connection between the ports 2I5 and 2I6 is cut off when the piston I 51 is in its normal right hand position; when said piston moves to the left for gage retraction, the reduced portion 2I9 of said piston permits fluid 70 under pressure to enter the motor I15.

Directly above the reduced portion I69 of the valve I65 is a full-sized portion 220 which prevents fluid connection between the port I61 and an adjacent port 22I, the latter being connected the piston. Directly above the port 22I and axial- 1y spaced therefrom, is a port 223 connected by a pipe 224 to a port 225 connecting with the extreme left hand end of the table cylinder. The casing I64 also has a port 226 opposite to, but spaced axially of said casing from the port 22I. Fluid connection between the ports 22I and 225 is normally prevented by spaced full-sized portions 221 and 223 on the piston valve, the latter full sized portion also preventing fluid connection between the port 226 and the port 223, above referred to. Fluid connection between the ports 2 I 3 and 223 is normally prevented by spaced fullsized portions 229 and 230 on the valve I65. when the valve I65 is moved into its upper position, fluid connection is provided between the ports 22I and 226 and also between the ports 2I6 and 223, for a purpose which will hereinafter appear. The port 226 is connected by a pipe 23I to a channel 232 intersecting the chamber 2 adjacent the lower portion thereof for admitting fluid to said chamber.

When fluid under pressure is directed through the pipe I68 into the casing I64, the fluid pressure in said casing moves the valve I65 upwardly to establish fluid connection between the left hand end of the table cylinder and the port 2I6 through the pipes 2 I1 and 224. At the same time the fluid under pressure in the pipe I62 moves the piston I51 to the left and establishes fluid connection directly from the table cylinder through the port 2I6 to the channel 2I3 in the ejector motor. At this time the left'hand end of the table cylinder is connected to the exhaust port 29 through the pipe 22. When the piston 26 closes the port 25, during movement of the table to the left, a further movement of the table builds up a pressure in the left hand end of the table cylinder which is sufficient to procure a turning movement of the vane 2"], the latter being connected through the pipes 2I4, 2" and 224 to the table cylinder. Clearly, the quantity of fluid remaining in the left hand end of the cylinder after the port 25 is closed, is necessarily more than suflicient to oscillate the vane from the normal position shown, into its opposite end position, shown in dotted lines in Fig. 8.

when the vane 2I0 reaches its lower or dotdash line position of Fig. 8, the ejector at this time being in the raised (dot-dash line) position of Fig. 2, the fluid under pressure in back of the vane passes through a by-pass channel 233 and a spring controlled valve 234 into the pipe 23I, thus allowing fluid to discharge from the left hand end of the table cylinder 24 for a slight additional movement of the table to the left after the ejector reaches its upper position, at which time a dog 235 carried on the table engages and actuates the reversing member I2. Said dog, as best shown in Fig. 6, has acam surface 236 engageable with the upper end I45 of the bell crank lever I42 for depressing the latter sumciently to permit said dog to engage the lug I4 on the reversing member.

Reversal of the valve I8 directs fluid under pressure through the pipes 222 and 23I into the lower portion of the fluid motor I15. The valve 234 now being closed, fluid under pressure beneath the vane 2IIl swings said vane upwardly, the fluid from above said vane discharging through the pipes 2I4, 2I1 and 224 into the left hand end of the table cylinder for moving the table to the right. When the vane 2I0 reaches its uppermost podtion, fluid under pressure passes through a by-pass channel 231 and past a spring-pressed valve 233, thus permitting fluid under pressure to enter the left hand end of the table cylinder until the piston 23 therein uncovera the port 25. Thereafter, the movements of the piston 26 are controlled by fluid under pressure in the pipes 2| and 22 in the usual manner.

During the return of the table to operative position, a depending dog 233 pivoted on a pin 246 on a block 24I on the front of the table engages the upper end of the bell crank lever I42, moving the latter downwardly and the arm I31 counter clockwise to return the valve H to its original position, the latch I34 engaging in the notch I35 to hold the arm I 31in position. The return of the valve H to its original position cuts off the flow of fluid under pressure to the upper end of right for releasing the gage so that the latter may operate in the usual manner during the subsequent grinding operation.

As best shown in Fig. 1, the bell crank lever I5I is reset to its original position, when the table reaches the end of its movement to the left, by a bracket 242 secured to the control box 46, said bracket having a flat upper surface engaging with the arm I53 of said lever, turning said lever counterclockwise in readiness for actuation thereof during the subsequent grinding opera- The operation of the machine, which will be clear from the foregoing description, will be briefly summarized. With the table in the position of Fig.'1, this being its position at the end of the movement thereof to the left, the ejector is in the upper position of Fig. 2, and the dog 235 has just actuated the reversing member I2 for returning the table to operative position. At this time, the valve 1I, Fig. 9, is in its right hand position providing fluid connection from the pump to the under side of the valve I65, the latter being'in its raised position. The vane 2I6 at this time is in the dot-dash line position of Fig. 8. Fluid under pressure passing the reversing valve I6, the latter being in the position of Fig. 9, enters the ejector motor I15 through the pipe 23I, thereby returning the ejector to its original position, and at the same time procuring a movement of the table to the right. As this movement continues, and after the ejector vane 2) reaches its upper position, fluid under pressure passes the valve 236 and enters the left-hand end of the table cylinder until the port 25 is uncovered, fluid under pressure then passing through the pipe 22 for continuing the movement of the table. Thereafter, during the movement of the table to the right, the'dog 233 returns the bell crank lever I42 and the arm I31 to the original position of Fig. 1 in readiness for the subsequent grinding operation, said dog also resetting the valve 1I through the arm I31.

As the table approaches operative position with the grinding wheel located within the bore 0f the workpiece, the reversing dogs 3 and 3 be- 75 come operative for controlling the reciprocations of the table. The crossfeed movement which was initiated when the valve 'II was reset by the dog 23! advances the grinding wheel against the surface of the workpiece for a cutting operation which continues until the workpiece is sufficient- 1y large to permit entry of the gage HI within the bore thereof.

When the gage enters the workpiece, the amplifled right .hand movement thereof swings the bell crank lever Iii, moving the end of said lever into alinement with the lever I32, so that during the subsequent right hand movement of the table, said lever releases thearm I31 and the latter moves to the right into the position of Fig. 6. This movement procures an extended movement of the table to the left by rendering inoperative the dog 9, and also procures, as above pointed out. a retraction of the crossfeed movement. As the table begins its extended movement to the left, fluid under pressure enters the bore I56 in back of the piston I51 for retracting the gage from within the bore of the workpiece. After the gage is fully retracted, fluid connection is provided between the left hand end of the cylinder and the upper end of the ejector motor I15. When the table piston 26 has closed the port 25 during the table movement to the left, the fluid to the left of said piston discharges into the upper end of the ejector motor and swings said vane downwardly, thereby raising the ejector for discharging the finished workpiece. As the ejector begins its upward movement, the pressure roll I08 is retracted, as above indicated, and when the ejector reaches its uppermost position, an unground workpiece is released.

when the ejector reaches its upper position, the vane 2 i being then in its lowermost position, fluid from the left hand end of the table cylinder is allowed to discharge through the by-pass channel 233, and the slight additional left hand movement of the table provided thereby permits the dog 239 to actuate the reversing valve. The grinding operation is then repeated in the manner above outlined. It will be noted that the fluid remaining in the left hand end of the cylinder after the port 25 is closed is always slightly more than the amount of fluid required for actuating the ejector motor to assure movement of the ejector arm through its entire cycle, thus making certain the discharge of the ground work piece and the insertion of an unground workpiece while the wheel is spaced axially from the worksupporting structure and while the gage is out of alinement with the work.

From the foregoing, it will be apparent that the present invention provides for a positive actuation of the ejector by fluid under pressure and is so interconnected with the table actuating mechanism that the ejector must move through its predetermined cycle before the table can be reversed for returning said table to operative position for a subsequent grinding operation. In addition, the ejector motor and the gage mechanism are interconnected to prevent operation of the ejector whfle the gage is within the bore of the workpiece, thus avoiding jamming of the machine and damage to the gage mechanism. It will be noted that, if the gage is not retracted, the table will be brought to rest during its movement to the left by fluid trapped in the left hand end of the cylinder, the only escape for fluid, after the port 25 is closed by the piston, being into the ejector motor, fluid connection to said motor being provided only when the gage is fully retracted.

We claim,

1. In a grinding machine, a grinding member and a work-supporting member, a table on which one of said members is mounted, a gage member adapted to enter the workpiece when the latter reaches the desired size, means under the control of said gage for procuring a movement of said table for axial separationbetween said members. means for procuring a radial discharge of a workpiece from the work-supporting member, 10 fluid pressure means for actuating said discharging means, means for withdrawing the gage from within the bore of the workpiece-and means provid'ng for operation of said fluid pressure means only after the gage is withdrawn from within the bore of the workpiece.

2. In a grinding machine, a grinding member and a work-supporting member,- a table on which one of said members is mounted, a gage member adapted to enter the bore of a workpiece in the work-supporting member when the latter reaches the desired size, means under the control of said gage for procuring a movement of said table for axial separation between said members, means for procuring a radial discharge of a workpiece from the work-supporting member, means for withdrawing the gage from within the bore of the workpiece and means providing for the operation of said discharging means only after the operation of said withdrawing means by which the gage is withdrawn from the bore of the workpiece.

3. In a grinding machine, a grinding member and a centerless work-supporting member, means governed by the progress of the grinding operation for procuring an axial separation between said members when a workpiece in the work-supporting member reaches the desired size, an ejector, and fluid pressure means responsive to and automatically operable during the axial separation for actuating said ejector.

4. In a grinding machine, a grinding member and a oenterless work-supporting member, a table on which one of said members is mounted, means governed by the progress of the grinding operation for procuring a movement of the table for an axial separation between said members when a-workpiece in the work-supporting member reaches the desired size, an ejector, and fluid pressure means responsive to said table movement and automatically operable during the axial separation for actuating said ejector.

5. In a grinding machine, a grinding member and a centerless work-supporting member, a table on which one of said members is mounted, a fluid pressure motor for actuating said table, means for procuring a movement of the table for an axial separation between said members, an ejector operable during the axial separation, and fluid pressure means connected to the table motor and actuated by the exhaust fluid from 60 said table motor for actuating the ejector.

6. In a grinding machine, a grinding member and a centerless work-supporting member, fluid pressure means governed by the progress of the grinding operation for procuring an axial separa- 65 tion between said members when the workpiece in the work-supporting member reaches the desired size, an ejector for procuring a radial discharge of the workpiece from the work-supporting member and fluid pressure means connected 7 to said first fluid pressure means and actuated by the exhaust fluid therefrom for actuating saidejector.

7. In a grinding machine, a grinding member and 'a centeriess work-supporting member, the

latter comprising a rotatable regulating wheel engageable with the periphery of a workpiece in saidsupporting member and a work-support, an

ejector for procuring a radial discharge oi the workpiece from the supporting member, size controlling means engagcable with the bore of the workpiece for controlling the grinding operation, means under the control of said size determining means for procuring operation of the ejector, means for withdrawing the size determining means from the bore of the workpiece, and means providing for operation of the ejector only after the operation of said withdrawing means.

8. In a grinding machine, a grinding member and a centerless work-supporting member, a table on which one of said members is mounted, an ejector for procuring a radial discharge of a workpiece from the supporting member, sizing means engageable with the bore of the workpiece for controlling the grinding operation, means under the control of said sizing means for procuring movement of the table for an axial separation between said members, means responsive to the table movement for actuating the ejector, means for removing the sizing means from within the bore of the workpiece and means associated with the sizing means to provide for the operation of the ejector only when the withdrawing means have fully withdrawn the sizing mean from the bore of the workpiece.

9. In a grinding machine, grinding member, a work-supporting member, an ejector for procuring discharge of a workpiece from within the work-supporting member, size determining means engageable with the bore of the workpiece, means for withdrawing the size determining means from within the bore of the workpiece, means for actuating the ejector, and means associated with said withdrawing means to provide for operation of the ejector actuating means only after the withdrawing means have fully withdrawn the size determining means from the bore of the workpiece.

10. In a grinding machine, a grinding member, a work-supporting member, an ejector for procurng discharge of a workpiece from within the wirk-supporting member, size determining means engageable with the bore of the workpiece, means under the control of said size determining means for procuring operation of the ejector, means for withdrawing the size determining means from within the bore of the workpiece, and means providing an interconnection between said withdrawing means and said actuating means to provide for operation of the ejector operating means only after the withdrawing means have fully withdrawn the size determining means from within the bore 01' the workpiece.

11. In a grinding machine, a grinding member, 25. work-supporting member, an ejector for procuring discharge of a workpiece from within the work-supporting member, size determining means engageable with the bore of the workpiece, means under the control of said size determining means for procuring operation of the ejector, means for withdrawing the size determining means from within the bore of the workpiece, and means providing an interconnection between said withdrawing means to provide for operation of the ejector operating means only after the withdrawing means have fully withdrawn the size determining means from within the bore 01 the workpiece.

12. In a grinding machine, a grinding mem ber and a work-supporting member, a table on which one of said members is mounted, said 6 table procuring a relative axial movement between said members, an ejector for removing a finished workpiece from the work-supporting member, size determining means, means under the control of said size determining means for procuring movement of the table for an axial separation between said members, fluid pressure means for actuating the ejector while said members are separated, means for withdrawing the size determining means from engagement with the workpiece, and means associated with said withdrawing means to provide for operation oi. said fluid pressure means only when the size determining means are out of engagement with the workpiece.

13. In a grinding machine, a grinding member and a work-supporting member, a table on which one of said members is mounted, said table procuring a. relative axial movement between said members, fluid pressure means for actuating said table, an ejector for removing a finished workpiece from the work-supporting member, fluid pressure means for actuating the ejector, and means providing a connection between the table actuating means and the ejector actuating means for directing exhaust fluid from the table motor to the ejector motor for actuating the latter.

14. In apparatus of the class described, a fluid motor comprising a piston and cylinder, means for directing fluid under pressure alternately to opposite sides of said piston for actuating the same, a second fluid motor, and means controlled by the position of the piston for directing the exhaust fluid from one side of the piston during a predetermined portion of its stroke to said second motor for actuating the latter during movement of the piston within the cylinder.

15. In apparatus of the class described, a fluid motor comprising a piston and cylinder, means for directing fluid under pressure alternately to opposite sides of said piston for actuating the same, a second fluid motor, means connecting one end of said cylinder to said second, fluid motor, means controlled by the position of the piston for cutting ofi the exhaust of fluid from said cylinder before the piston therein reaches the end of its stroke for directing the exhaust fluid during the remainder of said stroke to said second fluid motor for actuation of the latter during a predetermined portion of the piston movement, and means operative upon reversal of said second fluid motor for directing the exhaust fluid from said second motor to said flrst motor for actuating the latter.

16. In apparatus of the class described, a fluid motor comprising a piston and cylinder, valve means for directing fluid under pressure to said cylinder alternately at opposite sides of the piston for actuating the latter, said valve means 65 being shifted in response to movement of the piston within the cylinder, a second fluid motor, means for directing the exhaust fluid from the first motor to said second motor for actuating said second motor during a portion of the piston movement as the latter reaches the end of its stroke, and means operative upon reversal of said valve means for directing the exhaust fluid from said second motor to said first motor for actuating the latter.

17.. In apparatus of the class described, a fluid motor comprising a piston and cylinder, means for directing fluid under pressure alternately to opposite sides oi. said piston, including a port in the cylinder spaced from one end thereof, a second fluid motor, means connecting said one end of the cylinder to said second fluid motor for actuation of the latter by the exhaust fluid in the first motor after the piston therein has closed the port, and means operative upon reversal of said second fluid motor for directing the exhaust fluid from said second motor to said first motor for actuating the latter.

18'. In apparatus of the class described, a fluid motor comprising a piston and cylinder, valve means for directing fluid under pressure alternately to opposite sides of the piston for movement thereof relative to the cylinder, said valve means being reversed at opposite ends of the piston stroke in resppnse to movement of said piston, a second fluid motor including a piston and cylinder, means for actuating said second motor by the exhaust fluid from one side of the piston of the first motor during a portion of the movement of the latter piston as it reaches the end of its stroke, and means operative upon reversal of said valve means for directing exhaust fluid from said second motor to said first motor for actuating the latter.

19. In apparatus of the class described, a fluid motor comprising a piston and cylinder, means for directing fluid under pressure alternately to opposite sides of the piston for movement thereof relative to the cylinder, a second fluid motor including a piston and cylinder, means for actuating said second motor by the exhaust fluid from one side of the piston of the first motor, m eans operative upon reversal of said first motor for directing exhaust fluid from said second motor to said first motor for actuating the latter, and a by-pass in said second motor to provide for discharge of fluid through said motor for a continued movement of said first motor when the piston of the second motor reaches the end of its stroke.

20. In apparatus of the class described, a table having operative and an inoperative position, a fluid motor including a cylinder and piston for actuating said table, means responsive to the table movement for reversing the flow of fluid to said cylinder, a second fluid motor, means operative during the movement of the table into inoperative position for directing exhaust fluid from said first motor to said second motor for actuating the latter, and means operative on reversal of the table movement for directing fluid under pressure to said second motor and for directing the exhaust fluid from said second motor to the first motor for actuating the latter.

21. In a grinding machine, a grinding member and a work-supporting member, a table for one of said members, movement of said table procuring an axial separation between said members, a fluid motor for said table, means responsive to the movement of said table for reversing the direction of movement thereof, an ejector for workpieces in said work-supporting member, a

fluid motor for actuating said ejector, means responsive to movement of the table for actuating said ejector, means operative upon reversal of the I table movement for procuring a return of the ejector to original position, said fluid motors being interconnected to provide for a return of the ejector before the table returns to operative position with the grinding member engaging with a workpiece in the work-supporting member.

'22. In a grinding machine, a grinding member, a centerless work-supporting member, a table on which one of said members is mounted, fluid pressure means for actuating said table, means for on which one of said members is mounted, fluid pressure means for actuating said table, means for procuring a movement of said table for an axial separation between said members, an ejec- 20 tor for procuring discharge of a workpiece from the work-supporting member, a fluid pressure motor for actuating said ejector, means for actuating said fluid pressure motor by the exhaust fluid from the table actuating means during the axial 25 separation, and means operative upon reversal of the table movement for actuating the table motor by the exhaust fluid from the ejector motor.

24. In a grinding machine, a grinding member, a centerless work-supporting member, a table on which one of said members is mounted, fluid pressure means for actuating said table, means for procuring a movement of said table for an axial separation between said members, an ejector for procuring discharge of a workpiece from the work-supporting member, a fluid pressure motor for actuating said ejector, means for actuating said fluid pressure motor by the exhaust fluid from the table actuating means during the axial separation, and means operative upon reversal of the table movement for procuring return of said ejector to original position before the return of said members to operative position.

25. In a grinding machine, a grinding member and a centerless work-supporting member, a table on which one of said members is mounted, a fluid pressure motor for actuating said table, means for procuring a movement of the table for an axial separation between said members, an ejector for a workpiece in the work-supporting member and fluid pressure means connected to the table motor and actuated by the exhaust fluid from said motor for actuating the ejector.

26. In a grinding machine, a grinding member and a work-supporting member, a table on which one of said members is mounted, said table procuring a relative axial movement between said members, an ejector for removing a finished workpiece from the work-supporting member, size determining means, means under the control of said size determining means for procuring movement of the table for an axial separation between said members, fluid pressure means for withdrawing the size determining means from the workpiece, fluid pressure means for actuating the ejector while said membersare separated, and means associated with said withdrawing means to provide for operation of said ejector operating means only when the size determining means are out of engagement with the workpiece.

27. In apparatus of the class described, a table having operative and an inoperative position, a fluid motor including a cylinder and piston for actuating said table, means responsive to the table movement for reversing the flow oi fluid to said cylinder, a second fluid motor, means operative during the movement of the table into inoperative position for directing exhaust fluid from said flrst motor to said second motor for actuating the latter, means operative on reversal oi the table movement for directing fluid under pressure tosaid second motor and for directing the exhaust fluid from said second motor to the flrst motor for actuating the latter, and a bypass in said second motor to provide for discharge of fluid through said motor for a continued movement of said flrst motor when the piston oi the second motor reaches the end of its stroke.

28. In a grinding machine, a grinding member, a centerless work-supporting member, a table on which one of said members is mounted, fluid pressure means for actuating the table, means for procuring a movement of said table for an axial separation between said members, an ejector for procuring discharge of a workpiece from the work-supporting member, a fluid pressure motor for actuating said ejector, means for actuating said fluid pressure means by the exhaust fluid from the fluid pressure motor, and a by-pass in said fluid pressure motor to provide for discharge of fluid through said motor for a continued operation of said fluid pressure means when the fluid pressure motor reaches the end of its stroke.

29. In a grinding machine, a grinding member and a work-supporting member, fluid pressure means for procuring an axial reciprocation between said members and an'elongated movement of separation between said members, an ejector i'or procuring discharge of a workpiece from a work-supporting member, a fluid pressure motor for actuating said ejector, interconnecting means between said motor and said fluid pressure means for actuation of said ejector in response to operation of said fluid pressure means, a gage, fluid pressure means for withdrawing the gage from the workpiece, and a valve in said interconnecting means to provide for the flow of fluid from the fluid pressure means to the fluid pressure motor only when the fluid pressure means for withdrawing the gage is operative.

30. In apparatus of the class described, a worksupporting structure comprising a rotating drive wheel engageable with the periphery of a workpiece, a supporting member engaging said workpiece and a pressure member holding said workpiece against said wheel and supporting member, a plug gage adapted to enter the bore of the workpiece when the latter reaches a desired size, means under the control of said gage for procuring a radial discharge of a workpiece from the work-supporting structure, means for withdrawing the gage member from within the bore of the 5 workpiece, means for actuating said discharging means, and means providing for operation of said actuating means only after the operation of said withdrawing means by which the gage is removed from the bore 01' the workpiece. 10

31. In a grinding machine, a grinding member, a centerless work-supporting member, a table on which one of said members is mounted, fluid pressure means for actuating the table, means for procuring a movement of said table for an 15 axial separation between said members, an ejector for procuring discharge or a workpiece from the work-supporting member, a fluid pressure motor for actuating said ejector, means for actuating said fluid pressure means by the exhaust 20 fluid from the fluid pressure motor, a by-pass in said fluid pressure motor to provide for discharge of fluid through said motor for a continued operation of said fluid pressure means when the fluid pressure motor reaches the end of its stroke, and 25 a second by-pass in said fluid pressure motor to provide for discharge of fluid through said motor for a continued operation of said fluid pressure means when the fluid pressure motor reaches the opposite end of its stroke. 3 32. In a grinding machine, a grinding member, a centerless work-supporting member, a table on which one of said members is mounted, fluid pressure means for actuating said table, means for procuring a movement of said table for an axial 85 separation between said members, an ejector for procuring discharge of a workpiece from the work-supporting member, a fluid pressure motor for actuating said ejector, size determining means engageable with the bore of the workpiece, means for withdrawing said size determining means from the bore of the workpiece, means for actuating said fluid pressure motor by the exhaust fluid from the table actuating means during the axial separation, and valve means associated with 45 said withdrawing means to provide fluid connection from the table actuating means to said fluid pressure motor, only when the gage is fully withdrawn from the bore of the workpiece.

HAROLD L. BLOOD.

WALTER H. PICKENER. 

